1. Field
The present disclosure relates to embodiments of systems and methods for compressing plasma. In certain such embodiments, a plasma toroid is compressed using a liquid metal funnel.
2. Description of the Related Art
Various systems for heating and compressing plasmas to high temperatures and densities have been described. One approach for accomplishing plasma heating and compression by spherical focusing of a large amplitude acoustic pressure wave in a liquid medium is described in U.S. Patent Publication No. 2006/0198486, published Sep. 7, 2006, entitled “Pressure Wave Generator and Controller for Generating a Pressure Wave in a Fusion Reactor”, which is hereby incorporated by reference herein in its entirety. In certain embodiments of this approach, a plurality of pistons is arranged around a substantially spherical vessel containing a liquid medium. A vortex or cavity is created in the liquid medium. The pistons are accelerated and strike the outer wall of the vessel generating an acoustic wave. The acoustic wave generated in the liquid medium converges and envelopes a plasma that is introduced into the vortex, thereby heating and compressing the plasma.
A pressure wave generator of the type described in U.S. Patent Publication No. 2006/0198486 can be employed in a Magnetized Target Fusion (MTF) reactor as described, for example, in U.S. Patent Publication No. 2006/0198483, published Sep. 7, 2006, entitled “Magnetized Plasma Fusion Reactor,” which is hereby incorporated by reference herein in its entirety. In certain such implementations, a magnetized plasma is introduced into a vortex that is created in the liquid medium, such as molten lead-lithium (PbLi). The acoustic wave produced by the impact of pistons surrounding the spherical reactor vessel can compress the magnetized plasma to high density and temperature.
In some embodiments of the above-described devices, compressed gas such as steam or air can be used to accelerate the pistons. Typically the desired piston impact velocity for plasma compression is of the order of 100 m/s, and so generally a compressed gas pressure of about 1,300 psi is used to accelerate the pistons. To achieve the symmetry of implosion that may be useful or desirable in some implementations, the timing of the piston firing, trajectory, and impact is precisely controlled for each piston. For example, for some plasma compression implementations, all the pistons preferably strike the vessel wall within about 1 μs of each other. In some such implementations, a servo control system can be used to measure precisely the position of each piston and control its trajectory to attain the requisite impact time.
Whilst certain embodiments of such mechanical compression systems are attractive from, for example, a cost perspective, certain such implementations may need frequent maintenance, especially in applications where the repetition frequency of piston firing is high.